package poly_method;

public class A extends B {//子类
    public int sum(int n1, int n2) {
        return n1 + n2;
    }

    public int sum(int n1, int n2, int n3) {
        return n1 + n2 + n3;
    }

    public void say() {//子类重写父类的方法
        System.out.println("子类A say()方法被调用");
    }
}
